Medical professionals and healthcare providers such as nurses and doctors routinely treat patients having surface wounds of varying size, shape and severity caused by skin ulcerations due to diabetes, venous stasis, post surgical infections, gangrenous lesions, decubitus ulcers, amputations, skin grafts, burns, and frostbite. Variations in wound type and other patient indications dictate variations in desired medications for treatment, such as antibiotics, growth factors, enzymes, hormones, protocols, such as delivery rates for medication and temperature control.
One particular area of concern involves foot or limb wounds in diabetic patients. It is known that foot wounds in diabetic patients represent a significant public health problem throughout the world. Diabetes is a large and growing problem in the United States and worldwide, costing an estimated $45 billion dollars to the U.S. health care system. Patients afflicted with diabetes often have elevated glucose and lipid levels due to inconsistent use of insulin, which can result in a damaged circulatory system and high cholesterol levels. Often, these conditions are accompanied by deteriorating sensation in the nerves of the foot. As a result, diabetics experience a high number of non-healing foot ulcers.
It is estimated that each year up to three million leg ulcers occur in patients in the U.S., including venous stasis ulcers, diabetic ulcers, ischemic leg ulcers, and pressure ulcers. The national cost of chronic wounds is estimated at $6 billion. Diabetic ulcers often progress to infections, osteomyelitis and gangrene, subsequently resulting in toe amputations, leg amputations, and death. In 1995, approximately 70,000 such amputations were performed at a cost of $23,000 per toe and $40,000 per limb. Many of these patients progress to multiple toe amputations and contralateral limb amputations. In addition, the patients are also at a greatly increased risk of heart disease and kidney failure from arteriosclerosis which attacks the entire circulatory system.
The conventional methods of treatment for non-healing diabetic ulcers include wound dressings of various types, antibiotics, wound healing growth factors, skin grafting including tissue engineered grafts, use of wheelchairs and crutches to remove mechanical pressure, and finally amputation. In the case of ischemic ulcers, surgical revascularization procedures via autografts and allografts and surgical laser revascularization have been applied with short term success, but with disappointing long term success due to reclogging of the grafts. In the treatment of patients with venous stasis ulcers and severe venous disease, antibiotics and thrombolytic anticoagulant and anti-aggregation drugs are often indicated. The failure to heal and the frequent recurrence of these ulcers points to the lack of success of these conventional methods. Accordingly, the medical community has a critical need for a low cost, portable, non-invasive method of treating diabetic, venous, ischemic and pressure ulcers to reduce mortality and morbidity and reduce the excessive costs to the health care system.
Most problematic of all is that treatment of diabetic foot ulcers has been focused on amputation and not on limb salvage, as many of the wounds have not been properly treated. Improper treatment can be attributed to lack of an easy and inexpensive treatment system and method and severe inconvenience to the patient in using current methods. There is a need to prevent amputation by healing such wounds, particularly at an early stage.
Furthermore, amputation for conditions such as foot ulcers and frostbite becomes less avoidable the longer the condition is either left untreated or is unsuccessfully treated. Therefore, it is crucial to apply an effective treatment regimen as soon as possible. Unfortunately, foot wounds in patients with, for example, diabetes develop because of a process called neuropathy. Diabetes causes loss of sensation such that skin injury and complete breakdown (ulcer) can develop with no or minimal pain. These wounds tend not to heal because of ongoing mechanical trauma not felt at all by the patient as painful. Therefore, by the time the patient discovers the wound, the wound has often progressed so that the patient's treatment options have become severely limited.
In many cases, such wounds can only be healed by protecting them from mechanical trauma. Small plantar ulcers in diabetic patients area usually seen by primary care practitioners and endocrinologists. The present method for healing plantar ulcers is a total contact cast for the foot, which provides complete mechanical protection. This method is not ideally suited for either of these practice settings, because it requires skilled and specialized care in application, along with frequent follow up. Most patients perceive the cast to be an inconvenience at the early stages of such a wound, while perceiving that such a wound is not a serious matter. The alternative to the cast is to ask the patient to be non-weight bearing through the use of a wheelchair, crutches, or a walker, which provide complete mechanical protection only with complete patient compliance. This alternative rarely proves to be effective in healing wounds within a reasonable time period.
What is needed is a treatment that primary care physicians and their staff can employ to treat ulcers and other wounds that does not require extended physician time and that is effective even at later stages of wound progression. Also, what is needed is a treatment that allows patients to be able to continue their active lives without the need to wear casts, or be confined to wheelchairs and crutches.